Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons.
We have authentic narrations in Shia and Sunni books from the Prophet Muhammad (SAWA) stating that wearing gold is not allowed for men as well as wearing pure silk. Regarding gold we have an authentic Hadeeth from Ali ibn Jafar from his brother Imam Musa ibn Jafar (AS) when he was asked: Is it allowed for man to wear gold? He replied: No, because the Prophet (SAWA) did not allow it. ( Wasaa'il al-Shia, V.4, P.415). We have also a narration from Ammar ibn Moosa from Imam Jafar Al-Sadiq (AS): man should never wear nor pray with gold. (Wasaa'il al-Shia , V4, P. 413).
In Sunni books, Tirmithi and Ibn Hanbal and many others narrated that the Prophet (SAWA) said: Silk and gold are forbidden on the men of my Ummah, permissible for their women.
That is why it is unanimous among Muslim scholars from all Muslim sects that wearing gold ands silk is forbidden for Muslim men.
From a shar'i perspective, he is permitted to sleep on pure silk. The only prohibition is for a male to "wear" pure silk.
And Allah knows best.
It is haram for a male to wear "pure" silk, not mixed with any other material. But if it is satin, or a mixture of materials, then there would be no shar'i problem.
That being said, the Islamic etiquette of clothes is that a male wear clothes suitable for a man and brings about masculinity. The clothes do not necessarily need to be coarse or harsh, but also not soft and would suit more the feminine taste.
With prayers for your success.
According to Ayatullah al-Khu`i: Wearing a dress made of 100% silk is haram for men at all times.
However, he says: "There is no problem in carrying it [an item made from 100% silk] in salat and outside salat or in using it as bed-sheet or mantle --- as long as these items are not identified as `dress'.
"And there is no problem in making the hem of dress with it [100% silk] although it is ihtiyat wajib that the hem should not be more than four fingers in width.
"And there is similarly no problem in using it [100% silk] for waist-band...lace/braid...even the inner-linning of suits, etc.
"But a dress (libas) which is not sufficient [by itself for appropriate covering] in salat, then it is ihtiyat wajib to refrain from it." (Minhaju 's-Salihiyn, vol. 1, p. 139)
& ** In both these cases, Ayatullah Sistani says it is ihtiyat mustahab, not wajib. (Minhaju 's-Salihiyn, vol. 1, p.179)
In the light of the above, the use of a dress with pocket square would be allowed. About the neck-tie, I am still not sure how we would classify it -- as an item of dress or a decorative part of it?